test_tool_retry_multiple_middleware_composition() — langchain Function Reference

Source Code

libs/langchain_v1/tests/unit_tests/agents/middleware/implementations/test_tool_retry.py lines 867–909

def test_tool_retry_multiple_middleware_composition() -> None:
    """Test ToolRetryMiddlewarecomposes correctly with other middleware."""
    call_log = []

    # Custom middleware that logs calls
    @wrap_tool_call
    def logging_middleware(
        request: ToolCallRequest, handler: Callable[[ToolCallRequest], ToolMessage | Command[Any]]
    ) -> ToolMessage | Command[Any]:
        if request.tool:
            call_log.append(f"before_{request.tool.name}")
        response = handler(request)
        if request.tool:
            call_log.append(f"after_{request.tool.name}")
        return response

    model = FakeToolCallingModel(
        tool_calls=[
            [ToolCall(name="working_tool", args={"value": "test"}, id="1")],
            [],
        ]
    )

    retry = ToolRetryMiddleware(max_retries=2, initial_delay=0.01, jitter=False)

    agent = create_agent(
        model=model,
        tools=[working_tool],
        middleware=[logging_middleware, retry],
        checkpointer=InMemorySaver(),
    )

    result = agent.invoke(
        {"messages": [HumanMessage("Use working tool")]},
        {"configurable": {"thread_id": "test"}},
    )

    # Both middleware should be called
    assert call_log == ["before_working_tool", "after_working_tool"]

    tool_messages = [m for m in result["messages"] if isinstance(m, ToolMessage)]
    assert len(tool_messages) == 1
    assert "Success: test" in tool_messages[0].content